ESTRO 2020 Abstract book

S513 ESTRO 2020

We conducted a retrospective review of the medical records of patients with PPTID treated at our institution between 2011 and 2018. Clinical data, performance status, histology, imaging reports, type of resection, details of systemic therapy, details of RT, toxicity data, response to treatment and patterns of recurrence were gathered. Results Seven patients with a histological diagnosis of PPTID were identified including four males and 3 females. The median age at diagnosis was 35.7 years (range 15 – 54). Five patients had grade 2 PPTID, 1 patient had grade 3 PPTID and the grade was indeterminate in 1 patient. Three patients had complete resection whilst 4 had subtotal resection. One patient had spinal disease and received craniospinal RT. MRI Spine and CSF cytology were negative in the other 6 patients who received whole brain RT plus a boost to the tumour bed. The median dose was 56 Gy. Four patients had chemotherapy as part of their primary treatment. Three patients progressed one of whom received further stereotactic RT to the recurrent disease in brain and spine and further chemotherapy. Two of these patients died and 1 is currently living with disease. Four patients are alive and well with no evidence of recurrent disease. The median follow up duration was 3.2 years. The median progression free survival was 32.6 months and the overall survival 38.9 months Conclusion PPTID’s constitute 10% of all pineal parenchymal tumours. The aggressiveness of these tumours varies widely and optimal management guidelines are currently lacking. The role of craniospinal RT as well as the optimal RT dose remains a matter of debate. Our study showed that patients who had complete resection and had adjuvant RT and chemotherapy had improved survival compared to those who had subtotal resection. Whole brain RT plus a tumour bed boost seems to confer reasonable tumour control especially in those who had complete excision. A multi-institutional study with a larger patient cohort is required to determine better management guidelines for these rare tumours. PO-0872 Craniopharyngiomas treated with Fractionated Stereotactic Radiotherapy (FSR) R. Ching Lopez 1 , I. Tovar Martín 1 , R. Del Moral Ávila 1 , A.M. Ruiz Martínez 1 , S. Rodríguez Pavón 1 1 Hospital Universitario Virgen de las Nieves, Radiation Oncology, Granada, Spain Purpose or Objective Craniopharyngiomas are uncommon locally aggressive tumors that are usually located in the sellar and suprasellar regions, which makes their therapeutic approach a challenge. The optimal treatment requires an experienced multidisciplinary team (neurosurgery, radiotherapy, neuro-oncology, endocrinology, ophthalmology). Our aim is to analyze the results of the treatment of craniopharyngiomas with Fractionated Stereotactic Radiotherapy (FSR), by retrospective study of our data. Material and Methods From April 2005 to December 2017, 42 patients with craniopharyngiomas have been treated in our centre. Average age of 31 years (6-72), 64% women and 36% men. Most suprasellar tumors (60%), the main indication for treatment being postoperative residual tumor (65%), with proximity to the optic chiasm in 53%. The dose was 50Gy in 25 fractions (2Gy/fraction, 5 fractions/week), by LINAC with one isocenter and 10 fields. Results The median follow-up was 29 months. At the end of the study, 36.4% stabilization, 42.4% decrease in tumor size and 9.1% complete response. Only 12.1% progression. In relation to the clinical situation, 67.7% stabilization of symptoms and 16.1% improved their quality of life. 16.1% registered clinical worsening. Among the patients with

RPA III group (patients with KPS<70) survival time was only 2.2 months. It is similar to that achieved after symptomatic medical management. PO-0870 Impact of GTV on overall survival of Glioblastoma, post definitive therapy: a retrospective study. S. Bansal 1 , M. Bhattacharyya 1 , A.K. Kalita 1 , G. Sarma 1 , P.P. Medhi 1 , B. Sarma 1 , G. Bora 1 1 Dr. B Borooah Cancer Institute, Radiation Oncology, Guwahati, India Purpose or Objective To analyse the overall survival of Glioblastoma patients treated at our center and its correlation with GTV and other clinical parameters. Material and Methods From January 2016 to December 2018, medical records of the patients treated with surgery followed by postoperative chemo-radiation followed by adjuvant Temozolamide were retrieved. Postoperative residual Gross tumour volume (GTV) was calculated from treatment planning system (CMS XIO version 4.80). Patient and tumour characteristics were recorded for statistical analysis by SPSS v20. Results Data of total 38 patients was retrieved. Seven patients did not complete the treatment and expired before starting the treatment, or during the course of treatment. Median age at presentation was 51.5 years. 31 patients completed the prescribed treatment i.e. surgery followed by post- operative chemo-radiotherapy followed by adjuvant Temozolmide. Out of 31 patient, data of three patients could not be obtained and only 28 patients were available for final analysis. Overall median survival was 25 months (Males 25 months and females 17 months, p value >0.15). Median overall survival was 34 months in patients with post-operative GTV less than or equal to 70 cc compared to 25 months in patients with volume more than 70 cc (Hazard ratio 2.048, 95% CI 0.5-8.3, p-value 0.213). For patients with age more than 50 years median overall survival was 10 months compared to 34 months for age less than 50 years (p value<0.025). Conclusion Post-operative residual GTV ≤70 cc, male gender and younger age group (, 50 years) has been found to have better survival in our analysis. Further study with more number of patients is required to confirm the correlation. PO-0871 Outcomes in Pineal Parenchymal tumours of intermediate differentiation: A single institution study A. Glynn 1 , G. Rangaswamy 1 , J. O'Shea 1 , M. Dunne 1 , C. Faul 1 , D. Fitzpatrick 1 1 St.Luke's Radiation Oncology Network-Dublin-Ireland, Radiation Oncology, Dublin, Ireland Purpose or Objective Pineal parenchymal tumours are rare, accounting for <0.3% of all primary central nervous system tumours. Pineal parenchymal tumour of intermediate differentiation (PPTID) was first classified by the World Health Organisation (WHO) in 2000, as a tumour with an intermediate prognosis, between pineocytoma (WHO grade 1) and pineoblastoma (WHO grade 4). Mitotic index and immunohistochemistry are used to classify PPTIDs as grade II or III pathologically. Their clinical behaviour is variable and they present a risk of seeding to cerebrospinal fluid. Whilst the role of radiotherapy (RT) has been highlighted in various studies, the extent of RT has yet to be determined and the role of chemotherapy remains controversial. The aim of this study was to evaluate clinical outcomes in patients with PPTID who were treated with radical RT at our institution. Material and Methods